The present invention relates to a device for the non-rigid connection of pipes having circular cross-section, such as for example the pipes used in fittings for chemical reactors and distillation columns. The usual techniques for connecting such pipes include welding, shaping the tube ends, and various uses of gaskets, couplings, threadings, clamps, collars and the like. These techniques, however, are not satisfactory when the pipes to be connected are fragile as is the case, for example, with pipes made of plastics, glass, quartz or graphite, particularly when the pipes are of great length and must undergo conditions of vibration and high pressure.
In connecting pipes of these more fragile types, a flange system can be used whereby tightness is obtained with the help of flat gaskets but the strong force necessary to secure their tightening achieves at best a very rigid assembly extremely limiting the possibility of movement of the connected pipes and in fact often results in rupture of the flange. The conventional procedure used by glassblowers which consists of inserting tight cylindroconical mouthpieces and, exemplarily, a polytetrafluorethylene gasket is likewise unsatisfactory because of the high rigidity of the resulting system.
The need for an improved connecting device is particularly urgent in the design of plant-scale equipment for carrying out photochemical reactions. Such equipment involves reactors fabricated of metal containing liquid and/or gaseous reactants, usually under pressure which are caused to react under the influence of light. This light, exemplarily ultra-violet light, is supplied by submerging into the reactors a plurality of transparent pipes, exemplarily of glass or quartz, which contain sources of light radiation.
Such photochemical reactions are relatively easily carried out on a laboratory scale wherein the suitable emission of light can be directed to small cells containing the reactants and wherein the connection of the various parts of the apparatus presents no unusual difficulties. However, when these reactions are scaled up to plant operation, they present difficult and burdensome problems arising from the lack of a satisfactory system for joining the reactors to the glass or quartz pipes containing emitters of light, in particular of ultraviolet light.
In order to be sufficiently effective, these pipes must generally be two to three meters long and must operate under a pressure of about 2 to 10 bars, in addition to which they must also support the vibrations and forces due to the pressure differences existing between the reactor and the space enclosed by the pipes. Thus it is required to connect a fragile glass or quartz pipe entering the reactor to an accepting metal neck or sleeve on the reactor in a manner which is both leak proof and resistant to vibration and other mechanical disturbances. Conventional devices such as those described above are not satisfactory for such purposes.